SEASONAL CHANGES AND HISTORIES. 137 



the chrysalis hangs about twelve days, and by the 

 middle of July a new brood is on the wing, min- 

 gling with a few surviving parents. By mid- 

 August it is found in the greatest profusion, and 

 continues on the wing, in numbers constantly re- 

 duced by death, until October, when the surviv- 

 ors go into winter quarters, and before the end of 

 the month the last have disappeared. None of 



FIG. 126. Polygonia Faunns, nat. size ; under surface on left. 



these butterflies lay eggs until the following 

 spring. 



Another of the angle- wings, the Nettle Tortoise- 

 shell [Fig. 127], has a slightly different history, 

 flying, as it does, at three different times. The 

 hibernating butterflies appear by the middle of 

 March, in scanty numbers at first, more numer- 

 ously afterward, and continue on the wing until 

 nearly the end of May. They lay their eggs on 

 the young nettle plants late in April and early in 



